Fusible vent



5 1938. R. M. IVERSN ET AL 2,128,091

FUS IBLE VENT Filed April 1, 1935 INVENOR. NEWELL B. CASE. Roo:vcv M[VERSE/fil.

Patented Aug. 23, 1938 PATENT OFFICE FUSIBLE VENT Roderick M.

Iversen, Berkeley, Calif., and Newell B. Case, Seattle, Wash.

Application April 1, 1935, Serial No. 14,102-

12 Claims.

This invention relates to fusible vents for containers for flammable orexpansible liquids, gases or solid substances.

More particularly the invention relates to fusible vents or valves forvessels, tanks, reservoirs, piDesor tubes containing liquids, gasesorsolid substances which have the properties of expansien when subjectedto rising temperatures. A further object of the invention is theprovision of a fusible vent or valve establishing a positive means ofavoiding abnormal pressures Within such containers as those hereinbeforementioned, resulting from fire or being subjected to intense heat.

Another object of the invention is the provision of a fusible vent orvalve in which an element is employed having the characteristic ofmelting or softening at predetermined temperatures less than that-whichwould create an explosive pressure within the container.

More particularly, the invention relates to the provision of a fusiblevent or valve in which the fusible element is insulated against thecontents of the vessel, tank, reservoir, pipe or tube.

11; is well known that in many States and municipalities laws andordinances are in affect requiring that tanks and the like adapted tocontain flammable materials shall be provided With venting facilities ofsuch size and capacity as will safely relieve such interna] pressure asmay be created by exposure fires, and these rules also provide that ifsuch venting facilities incorporate a fusible element, the fusingtemperature of such element shall not exceed a certain number of degreesFahrenheit. Rules such as these have been proposed by nationalassociations, as for example, in a. code of good practice in theconstruction and operation of tank trucks, etc. for the transportationof fiammable liquids.

' It has been our experience, however, that fusible vents complying withthe aforementioned rules and regulations do not go far enough inproviding positive venting means in emergencies, such as exposure fires.Asfor example, we have found, in a number of experiments, that if afilled container having the conventional vent is exposed to fire, thecontents act as a heat conductor to such a considerahle degree that thefusing of the fusible element employed is dangerously retarded. That isto say, when fire occurs in the region of the venting device, thecontents tend to conduct the heat away from the fusible element andwhile retarding the fusing of the same, the pressure within thecontainer rapidly climbs to the danger line.

This is especially truc in cases where the tank or container is tiltedfrom its normal position to a point where the substance containedthereby lays against the venting device, and We have found in ourexperiments that the fusing of the 5 element is retarded in a measurabledegree.

With the results of these experiments in mind, we set about finding somemeans of insuring the melting of the fusible element regardless of thelevel of the contents of the container, and it is -10 believed that ourinvention accomplishes that end.

Referring now to the drawing forming a part of this specification:

Figure 1 is a top plan view of a fusible vent embodying our invention, aportion of the same being broken away to show relative position andarrangement of parts.

Figure 2 is a section taken along the line 2-2 of Figure 1.

Figure 3 is a top plan view of a different application of the principleof our invention.

Figure 4 is a section taken along the limes 44 of Figure 3.

Figure 5 is a sectional view of a portion of the vent shown in Figure 4With a breather pipe indicated therein.

Like numerals being used herein to indicate corresponding partsillustrated in the drawing, the numeral l designates a portion of anyconventional Vessel, tank, reservoir, pipe or tube adapted to containliquids, gases, or solid substances of an expansible or flammablenature.

Referring to the device shown in Figures 1 and 2, we provide a boss 2consisting of two sectors or sections 3 and 4 fitted together andriveted or otherwise secured in position in an appropriate orifice inthe container l by means such as the rivets 5. The inner section 4 ofthe boss 2 is threaded as at 6 to receive any conventional screvv plug,as for example that indicated by the numeral 1. It -Will also be notedthat the two sections 3 and 4 project into the container I (see Figure2) The two sections of the boss 3 and 4 have corresponding annularconcave recesses 8 which when fitted together form an annular boreadapted to contain the fusible element 9. To facilitate the pouring ofthe fusible element into this bore, vve have provided an intake il and avent Il], both communicating With said bore through the parts 3 and 4.

An annular arcuate recess 12 is disposed in the boss between the fusibleelement 9 and theinterior of the container I, the same being formed,55

by complementary recesses [3 and I4 in the parts 3 and 4 respectively,to provide an air cell or chamber or as a space adapted to contain anyknown insulating material.

From the foregoing description it will be obvious that the fusibleelement of the vent shown in Figures 1 and 2 is completely insulatedaway from the contents of the container l, as well as that portion ofthe boss 2 which projects into the container l. As a consequence of thisthe exposure of the vent, here illustrated and described,-

to fire or any intense heat Will concentrate such. heat on the fusibleelement and more quickly' cause the softening or melting of same. In theabsence of such insulation, as heretofore explained, the heat isconducted away from the fusible element, retarding the desirablefunction of the latter while dangerous pressures are being built upWithin the container.

It Will also be obvious that when the vent element is exposed toexcessive heat and a temperature is reached such as Will melt or softenthe fusible element 9, the inner portion 4 of the boss 2 Will be blownout by the increasing pressure Within the tank i. 'Ihus, an orificesuificient in siZe to reduce the pressure within the container 1 to lessthan the exploding point will be expeditiously provided.

The venting device shown in Figures 3, 4 and 5 is such as can beemployed in connection with fuel tanks for automobiles and other motorvehicles. In this instance we employ a boss i6, Which is riveted orothervvise secured to the tank l, as at H, and extends outwardly toprovide a spout l8 having conventional threads le, the latter beingadapted to be engaged by a cap 29 through the means of the correspondinginternal threads 2l.

Here we provide a conical-shaped emergency orifice 22 in the cap 21], toreceive the sealed hollow inner plug or cap 23. The plug 23, beinghollow, utilizes the air Within for the purpose of insulating thefusible element 24 disposed thereover, away from the contents of thetank, regardless of the position of the latter, whether it be in itsnormal position or an abnormal position as a result of accident or thelike.

Additional insulation is furnished by providing the cap With ahorizontally disposed annular recess 25, the inner part of which dropsdownwardly into the orifice 22.

In this adaptation of our invention, it will be appreciated, theinternal pressure of the container l blows the plug 23 out throughorifice 22 when the heat has melted or sufiiciently softened the fusibleelement 24. Melting or softening of the said fusible element 24 isfacilitated by the fact that the same is insulated with respect to notonly the contents of the container l but the greater portion of the cap20 and all of the boss. l6.

A conventional washer 26, of rubber or some other suitable material, isprovided between the boss [6 and the cap 20.

Since it is customary to provide the removable caps of fuel tanks ofautomobiles with a breather hole, we have made provision for the same inthe adaptation shown in Figure 4, attention being invited to Figure 5 ofthe drawing. A breather pipe 2! extends through the inner plug 23 andthe fusible element 24. This pipe is of sufficient diameter to relievenormal pressure only.

Whlle we have described recesses l2 and 25 of the two adaptations of ourinvention as air spaces, it should be appreciated that both of them maybe filled With known insulation materials if further experimentationproves this advisable. The same is true of the interior of sealed plug23, hence we do not wish to be understood as limiting ourselves to theuse of air filled chambers only.

It is believed that our discoveries overcome the 5 urgent need existingin all industries which employ emergency Vents of this general class,while at the same time providing an inexpensive means for a desiredpurpose. Having thus described our invention, what we claim and desireto secure by 10 grant of Letters Patent is:

.1. In a fusible vent, a boss adapted to fit into the wall structure ofthe article to be sealed,

said boss comprising inner and outer sectors, eacn of said sectorshaving a plurality o-f complemen- 15 tary recesses, one pair of opposedrecesses when fitted together defining an annular bore adapted toreceive a fusible binding element, and the other pair of opposedrecesses defining an air chamber.

2. In a fusible vent, a boss adapted to fit into the wall structure of atank, said boss comprising inner and outer sectors, one of said sectorshaving a plurality of complementary recesses, one pair of opposedrecesses defining a bore adapted to receive a fusible binding elementand the other pair of opposed recesses being adapted to define a chamberbetween said bore and the interior of said tank.

3. In a fusible vent, a boss adapted to fit into the wall structure of atank, said boss comprising inner and outer sectors, said sectors havingcomplementary recesses adapted to define a bore to receive a fusiblebinding element, and insulation means comprising an air chamber disposedin said sectors between said bore and the contents of said tank;

4. In a fusible vent, a boss adapted to fit into the wall structure of atank, said boss comprising inner and outer sectors, each of said sectorshaving a plurality of complementary recesses, one pair of opposedrecesses defimng an annular bore adapted to receive a fusible bindingelement, other pairs of opposed recesses defining intake and outletorifices in communication with the said bore, and another pair of saidrecesses defimng 5 an air chamber betWeen said bore and the interior ofsaid tank.

5. In a fusible vent, a cap threaded interiorly and adapted to engage athreaded spout, a conical-shaped orifice in said cap, an annular recessabout said orifice, a sealed hollow plug adapted to scat itself in saidorifice and close said recess, and a fusible element in said orificeabove said Pins.

6. In a fusible vent, a cap threaded interiorly and adapted to engage athreaded spout, an orifice in said cap, an annular recess about saidorifice, a hollow plug adapted to be seated in said orifice and closesaid recess, and a fusible element in said orifice above said plug.

'7. In a. fusible vent, a cap threaded interiorly and adapted to engagea threaded spout, an orifice in said cap, an annular recess about saidorifice, a .hollow plug adapted to be seated in said orifice and closesaid recess, a fusible element in said orifice abovesaid plug, and abreather pipe extending through said fusible element and said plug.

.8. In a fusible vent, a tank having an orifice therein, a closure forsaid orifice, an emergencywzo orifice in said closure, and closure meansfor said emergency orifice including a fusible element and aselfcontained insulating air chamber between said fusible element andthe interior .of the tank.

9. In a fusible vent, a boss adapted to fit intovg5 the wall structureof a tank, said boss comprising inner and outer sectors having aplurallty of complementar recesses, the outermost complementary recessesdefinng a bore, a fusible clement in the bore, the lnnermostcomplementary recesses definin an insulatlng air chamber lying betweenthe fusible element in said bore and the contents of said tank.

10. In a devlce of the character desczibed, a tank havirig an orificetherein, a closure for said orifice, an emergency orifice in saldclosure, and closure means for said emergency orifice including afusible element insulated from the contents of the tank by a closed airchamber dlsposed between sald fusible element and the lnterior of thetank.

11. In a device of the character described, a tank having an orificetherein, a closure for said orifice, an emergency orifice in saidclosure, and closure means for said emergency orifice including afusible element insulated from the contents of the tank by a closed airchamber lying beneath the entire area of said fusible element.

12. In a device of the character described, a tank having an orificetherein, a closure for said orifice, an emergency orifice in saidclosure, and closure means for said emergency orifice including afusible retainer therefor insulated against the contents of sad tank byan underlying air cell.

RODERICK M. IVERSEN. NEWELL B. CASE.

